WASHINGTON — Gays and lesbians are fighting for the same equal rights that African-Americans fought for decades ago, Vice President Joe Biden said Friday, on the eve of the 50th anniversary of the historic march in Selma, Alabama.

An early supporter of gay marriage, Biden sought to draw parallels between civil rights for gays and African-Americans as he addressed a summit of the Human Rights Campaign, a major gay rights group. Just as he could never have imagined serving alongside a black president, Biden said, he never anticipated seeing a time when gays would serve in the military openly, the Supreme Court would strike down anti-sodomy laws and a majority of U.S. states would legalize gay marriage.

"Selma and Stonewall were basically the same movement," Biden said, invoking the 1969 Stonewall Inn riots in New York that marked the symbolic start of the modern gay rights movement.

Biden's remarks come the day before President Barack Obama and surviving marchers were to gather at the Edmund Pettus Bridge in Selma to commemorate half a decade since white police officers beat civil rights protesters who were fighting segregation in the South. Reflecting on the number of southern states where gay marriage is still banned, Biden said the next step for activists is to help bring gay rights to the South.

Activists responded with fervent applause when he recalled announcing his own support for gay marriage during a 2012 television interview, putting pressure on Obama, who followed suit a few months later. "I told the president I wasn't going to change my brand," Biden said with a grin.

Presidential politics also popped up at the summit, where a brief mention of presumptive 2016 candidate Hillary Rodham Clinton drew a warm reaction and cheers.

In his speech, Biden — another possible 2016 contender — called out potential Republican candidate Ben Carson for saying that homosexuality was a choice and citing sexual activity in prisons as evidence.

"Every ridiculous assertion from Dr. Carson on, I mean, ridiculous," Biden said of the former neurosurgeon. He added, "I mean, Jesus, God."